Tag Archives: appetite

Roots of Temptation-Just Say No?

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Thanks to our brain’s complex pleasure/reward system, we all succumb to the pull of food differently. For some, the brain sometimes can’t resist the powerful influence of a fabulous bakery or a plate of French fries, yet others are able to eat a little and stop. But for millions of people, food is never far from their minds. Ever. The current trajectory of the number of obese Americans, along with related disease rates and health care costs, is on course to increase drastically in every state by 2030. The analysis findings, based on a model published last year in The Lancet, show that all 50 states could have obesity rates of more than 44 percent, with medical costs associated with treating preventable diseases soaring from $48 billion to $66 billion per year. By contrast though, according to a study released by Trust for American Health and the Robert Wood Foundation, reducing the average body mass index by just 5 percent could prevent an epidemic. For a 6-foot-tall person weighing 200 pounds, a 5 percent reduction would be the equivalent of about 10 pounds. The good news is that scientists are learning more about the cue-urge-reward-habit cycle of the human brain, so that a 5 percent loss may be quite attainable without entirely giving up your favorite foods.

Neurons and Taste

For some people, certain foods seem to exert a magical pull, writes former Food & Drug Commissioner Dr. David Kessler in his book “The End of Overeating.” The food industry works hard to create high-calorie foods with the most addictive possible combination of intense flavor and “mouth-feel.” In his book, Kessler tells how neurons, the basic cells of the brain, are connected in circuits and communicate with one another to store information, create feelings and control behavior. Tasting tantalizing food stimulates the brain neurons that are part of the opioid circuitry, which is the body’s primary pleasure system. Known as endorphins, these brain chemicals have the same addictive and rewarding effects as morphine and heroin.

The Roots of Temptation

No matter how good the intentions, avoiding fattening foods is always a challenge, and biology is a factor in why it seems so difficult to bypass a bowl of M&Ms. Brain chemicals are in more regions than previously thought. Researchers have traced an unexpected area of the brain in rats that had primarily been linked to movement. This new evidence might help explain why chocolate can be so irresistible and why we binge. Published this week in Current Biology, a Cell Press publication, the research team probed a brain region called the neostriatum, causing the rats to gorge on twice the amount of M&M chocolates than they would otherwise have eaten. The researchers found that a neurotransmitter called enkephalin, a drug-like chemical produced in that same region of the brain, surged as they ate more M&Ms. The chemicals increased their desire and impulses to eat more.

“That means the brain has more extensive systems to make people want to overcome rewards than previously thought,” said Alexandra DiFeliceantonio of the University of Michigan. “The same brain area we tested here is active when obese people see foods and when drug addicts see drug scenes.”

It’s likely that these neurotransmitters wire us for a little overconsumption and addiction. Understanding what triggers overeating and how our neural pathways can stump us can be useful the next time you walk down the potato chip aisle.  Five percent sounds like a good plan.

 

What Are You Hungry For?

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Stare long enough at carrot cake in front of you and you will eat it. eventually you’ll take a bite or two out of it. Even if you’re stuffed, weren’t that hungry, or don’t particularly like carrot cake.

 It’s not that easy control sometimes, because the psychological drive to eat, our “head hunger” can take over. Not only are triggers such as stress and anxiety the wrong reasons to eat, but biology, conditioning and metabolic influences also drive our appetites and hunger. Researchers are studying at least 70 receptor sites on individual brain neurons known to play a role in how hunger works to shed some light on our hunger mechanisms.

True hunger, the stomach-growling kind, is an intense feeling of having to eat something, resulting from low blood glucose. We’re faced with hundreds of food choices every day, of wanting to eat, but good food choices go out the window when you are this hungry. Nor does it help us that our supermarkets tempt us with 17,000 new products on the shelves yearly, most of them dense with calories and fat. To make matters worse, when you’re over-hungry or skip a meal, the body needs to make up for this missing blood glucose to sustain itself and uses the amino acid alanine,which is stored in muscle. Overtime your lean muscle shrinks, and your body becomes better at storing fat. A better way to control your weight and hunger is to eat small meals throughout the day. Researchers found that female gymnasts and runners who ate less than what was required of their sport during the day had the highest body fat levels. Other studies that looked at athletes showed the ones that ate smaller, more frequent meals and snacks, instead of bigger end- of- day meals, had lower body fat and lower overall insulin release.

We receive signals from the brain when we want to eat and when we’ve had enough, but they aren’t always reliable. Ghrelin is one of the hormones responsible for wanting to eat.  When you’re sleep-deprived, this same hormone amps up to drive us to eat more, and decreases the turn-off switch, leptin, that tells us we’re full. A recent Standford University study showed that adult men’s appetites for high fat food increased by 45% when they were getting less than 8 hours sleep a night. Interestingly enough, anorexics are masters of ignoring these strong signals to eat. These signals to eat, if we listen to them, can help us understand our eating behavior .It just might be that maybe you really are exhausted, and need a nap, or you might be dehydrated, because you haven’t been drinking enough water.  Dr. Barbara Rolls, professor of nutritional sciences at Pennsylvania State University, explains how you can eat normally, without dieting, if the foods you choose are simply less dense. For example, in her book, The Volumetrics Eating Plan,  a pale –looking traditional high-fat Shrimp Fried Rice, is transformed to one that includes broccoli, carrots, scallions, frozen peas, red and green bell pepper, fresh garlic and ginger. High fat-dense calories, like oil, are replaced by high fiber, lower calorie, nutrient rich vegetables.

It would be easy if there were just a pill to help curb our appetites and up our metabolism.  To date, 2 drugs are FDA approved and 300 clinical trials are underway that are tackling the complicated issue of obesity. The lifestyle changes involving diet and daily exercise are still your best bet to have a healthy, happy appetite for life!

Connie Aronson is an ACSM Certified Health Fitness Specialist, ACE Gold Certified Personal Trainer and an IDEA Elite Personal Trainer located at Koth Sports Physical Therapy in Ketchum. She is currently working on eating slower.

Published  August  10, 2007 in The Idaho Mountain Express.